INTENSIFYING THE COPPER ELECTRODEPOSITION PROCESS AT THE NORIL'SK MINING-METALLURGICAL COMBINE.

摘要

The enormous efforts made by the NGMK [Noril'sk Mining-Metallurgical Combine] to develop the theory and practice of electrolytic refining has resulted in a high level of hydrometallurgical intensification at its copper plant. The concentration of production has yielded positive effects, with some loss in extensive developments. It became possible to achieve a continuous increase in cathode copper output and to save tens of millions of rubles by eliminating the need for huge capital investments for new construction. It has also increased the daily productivity of baths by 75.3-78.6 percent, raised the labor productivity of industrial-production personnel by 67.0-71.5 percent, and reduced the amount of incomplete production per ton of cathodic metal by 43.8-46.4 percent and of steam consumption by 28.6-31.7 percent in 1986-1988 - as compared with 1960 indices. The increased daily productivity of electrolysis baths was accompanied by a rise in cathode current density (D_c) from 106 to 306-312 A/m~2 (occasionally, the average monthly current density was 315-330 A/m~2). It was not necessary to reconstruct the baths to expand the cathode surface. The current densities employed in the NGMK electrolysis shop (305-330 A/m~2) are not only the highest in USSR practice, but even exceed foreign levels - except for a number of enterprises which use current reversers [1, 2]. However, there are also some negative aspects to intensifying the process because it leads to reductions in a number of technological and social-economic indices: the current efficiency (eta), the coefficient of extensive bath use (K_i); it also induces more complaints about cathode deposit quality, requires greater labor-intensity to service electrolysis baths, increases processing costs (from 61.63 to 91.93 rubles/t), reduces capital funds efficiency, and leads to more work time lost. These trends increased sharply during 1985-1986 - the period when the Combine was switching to new cost accounting methods.